An MRAM (Magnetic Random Access Memory) is a memory device using a magnetic element having the magnetoresistive effect as a memory cell for storing information, and is attracting attention as a next generation, high speed, large capacity nonvolatile memory device. The magnetoresistive effect is a phenomenon in which when a magnetic field is applied to a ferromagnetic material, the electrical resistance changes in accordance with the magnetization direction in the ferromagnetic material. The MRAM can be operated as a memory device by recording information by using the magnetization direction in the ferromagnetic material, and reading the information in accordance with the magnitude of the corresponding electrical resistance. Recently, it has become possible to obtain a very high magnetoresistance ratio (MR ratio) of 100% or more by the tunneling magnetoresistive (TMR) effect. As a consequence, a large capacity MRAM including a magnetic tunnel junction (MTJ) element using the TMR effect is regarded as promising and attracting attention.